I want to have a better understanding of how to get precise measurements for True 50/50 longboard rails. So far I have been working with the exact middle of the boards thickness for my Apex line on the raw rails, which I measure from the bottom and then link all the dots. When I see videos of it, people seem to use fix measurements from the bottom at least for the center-third of the board.
The alternative to my version would be someone who doesn´t take the slightly domed deck in account and just orientates on raw rail band before going in to rail shaping, putting an apex line in the middle and alternating towards nose and tail.
What are your opinions on the topic, how do you guys decide how to choose the apex for classic longboards ? Do you have any good advice for sources where I can get detailed measurement examples?
PS: So far im always going for single to belly to vee.
Finding the Apex/ middle along the rail line is relatively easy, provided you work off a true vertical or 90 rail. In other words an outline that is true and squared up. Best tool touse is a carpenters combination square. Find the mid point thickness along the outline. Make a series of dots or pencil line along the center line. Determine how pinched you want the rail to be. Make marks along the middle line set back at 1/8”, 1/4”, 1/2” or whatever increment will result in the taper of the rail desired. Mark your rail bands top and bottom and plane away. If you just make a mark at center, you will have an extremely “pinched” rail. Once you have cut your deck and rail bands, you should still be able to see the pencil marks at the rail outline. Blend the rail with dragon skin or 60# sandpaper and then screen.
From what I have found on the internet, surfshopes etc. is that 50/50 is misused a lot. Yes the classic 50/50 apex, bang in the middle of the thickness foil exists and is still used quite often. However, even when described as 50/50 rails it is (from my experience) commonly seen that the rails drop down in the middle/WP of the board to a more 60/40 apex, while the tail and nose are more 50/50 apex or even ‘upturned’.
In those cases you could still see the rail curve from the bottom to the apex have a very similar ‘parabolic’ shape towards the apex, compare to the curve from the deck.
IMO, I read an article from Brock Jones, son of Bruce Jones, and he clearly advocates for a measurement of the apex and tuck, rather than using discriptions like 50/50, soft rails etc. When talking to other shapers. Keep in mind, brands like to be ambigious for marketing mumbo jumbo.
Pick a style or even go beyond and experiment, but go with what feels best.
Most of those words come from hand shaping era. Surf foam blanks have some dome so rail thickness is not center thickness. 50/50 are from rail thickness. I build my blank in eps bloc i measure rail apex from bottom.
